<template>
    <!-- 三级联动组件 -->
    <div class="type-nav">
        <div class="container">
            <div @mouseleave="curIndex = -1">
                <h2 class="all">全部商品分类</h2>
                <div class="sort">
                    <!-- 利用编程式导航+事件委派来时实现路由的跳转与传递参数 -->
                    <div class="all-sort-list2" @click="goSearch">
                        <!-- 一级分类 -->
                        <div class="item" v-for="(c1, index) in categoryList" :key="c1.categoryId"
                            @mouseenter="changeIndex(index)">
                            <h3 :class="curIndex === index ? 'cur' : ''">
                                <a :data-categoryName="c1.categoryName" :data-category1Id="c1.categoryId">{{
                                    c1.categoryName }}</a>
                            </h3>
                            <div class="item-list clearfix" v-show="curIndex === index">
                                <div class="subitem" v-for="(c2) in c1.categoryChild" :key="c2.categoryId">
                                    <dl class="fore">
                                        <!-- 二级分类 -->
                                        <dt>
                                            <a :data-categoryName="c2.categoryName" :data-category2Id="c2.categoryId">{{
                                                c2.categoryName }}</a>
                                        </dt>
                                        <!-- 三级分类 -->
                                        <dd>
                                            <em v-for="(c3) in c2.categoryChild" :key="c3.categoryId">
                                                <a :data-categoryName="c3.categoryName"
                                                    :data-category3Id="c3.categoryId">{{ c3.categoryName }}</a>
                                            </em>
                                        </dd>
                                    </dl>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
            <nav class="nav">
                <a href="###">服装城</a>
                <a href="###">美妆馆</a>
                <a href="###">尚品汇超市</a>
                <a href="###">全球购</a>
                <a href="###">闪购</a>
                <a href="###">团购</a>
                <a href="###">有趣</a>
                <a href="###">秒杀</a>
            </nav>
        </div>
    </div>


</template>
<script>
import { mapState, mapActions } from 'vuex'
import throttle from 'lodash/throttle'
export default {
    name: 'TypeNav',
    mounted() {
        this.$store.dispatch('home/categoryListAction')
    },
    data() {
        return {
            cur: 'cur',
            curIndex: -1,   //当前选中的索引
        }
    },
    computed: {
        ...mapState('home', ['categoryList']),
    },
    methods: {
        ...mapActions('home', ['categoryListAction']),
        changeIndex: throttle(function (index) {
            this.curIndex = index
        }, 50),

        goSearch(event) {
            // 获取当前触发事件的元素,及当前点击的具体元素
            let element = event.target;
            // console.log(element);
            // element.dataset 获取自定义属性及其值,是一个对象
            let { categoryname, category1id, category2id, category3id } = element.dataset;
            // console.log(element.dataset);

            let location = {
                name: 'search',
            };
            let query = { categoryName: categoryname }
            // 如果当前触发事件的元素是a标签
            if (categoryname) {
                // 一级分类
                if (category1id) {
                    query.category1Id = category1id
                } else if (category2id) {
                    query.category2Id = category2id
                } else if (category3id) {
                    query.category3Id = category3id
                }
            }
            location.query = query

            // 编程式路由跳转
            this.$router.push(location)
        }


    },

}
</script>
<style lang="less" scoped>
.type-nav {
    border-bottom: 2px solid #e1251b;

    .container {
        width: 1200px;
        margin: 0 auto;
        display: flex;
        position: relative;

        .all {
            width: 210px;
            height: 45px;
            background-color: #e1251b;
            line-height: 45px;
            text-align: center;
            color: #fff;
            font-size: 14px;
            font-weight: bold;
        }

        .nav {
            a {
                height: 45px;
                margin: 0 22px;
                line-height: 45px;
                font-size: 16px;
                color: #333;
            }
        }

        .sort {
            position: absolute;
            left: 0;
            top: 45px;
            width: 210px;
            height: 461px;
            position: absolute;
            background: #fafafa;
            z-index: 999;

            .all-sort-list2 {
                .item {
                    h3 {
                        line-height: 30px;
                        font-size: 14px;
                        font-weight: 400;
                        overflow: hidden;
                        padding: 0 20px;
                        margin: 0;

                        a {
                            color: #333;
                        }
                    }

                    .cur {
                        background: skyblue;
                    }

                    .item-list {
                        position: absolute;
                        width: 734px;
                        min-height: 460px;
                        background: #f7f7f7;
                        left: 210px;
                        border: 1px solid #ddd;
                        top: 0;
                        z-index: 9999 !important;

                        .subitem {
                            float: left;
                            width: 650px;
                            padding: 0 4px 0 8px;

                            dl {
                                border-top: 1px solid #eee;
                                padding: 6px 0;
                                overflow: hidden;
                                zoom: 1;

                                &.fore {
                                    border-top: 0;
                                }

                                dt {
                                    float: left;
                                    width: 54px;
                                    line-height: 22px;
                                    text-align: right;
                                    padding: 3px 6px 0 0;
                                    font-weight: 700;
                                }

                                dd {
                                    float: left;
                                    width: 415px;
                                    padding: 3px 0 0;
                                    overflow: hidden;

                                    em {
                                        float: left;
                                        height: 14px;
                                        line-height: 14px;
                                        padding: 0 8px;
                                        margin-top: 5px;
                                        border-left: 1px solid #ccc;
                                    }
                                }
                            }
                        }

                    }
                }

                .item.cur {
                    background-color: skyblue;
                }
            }
        }
    }
}
</style>
